309438581818 has 16 divisors (see below), whose sum is σ = 476798533920. Its totient is φ = 150507418896.

The previous prime is 309438581813. The next prime is 309438581833. The reversal of 309438581818 is 818185834903.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (309438581813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47688 + ... + 788131.

It is an arithmetic number, because the mean of its divisors is an integer number (29799908370).

Almost surely, 2^309438581818 is an apocalyptic number.

309438581818 is a deficient number, since it is larger than the sum of its proper divisors (167359952102).

309438581818 is a wasteful number, since it uses less digits than its factorization.

309438581818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840861.

The product of its (nonzero) digits is 6635520, while the sum is 58.

The spelling of 309438581818 in words is "three hundred nine billion, four hundred thirty-eight million, five hundred eighty-one thousand, eight hundred eighteen".